Absorbent press roll assembly



July 30, 1940.

E. E. BERRY 2,209,759 .ABSORBENT PRESS ROLL ASSEMBLY Filed June 28, 19572 Sheets-Sheet l EMEQ? U5 Zw EZB/W/ July so, 1940.

E. E. BERRY ABSORBENT. PRESS ROLL ASSEMBLY Filed JlinB"28, 1937 2Sheets-Sheet 2 7 UR El ar/y Patented July so, 1940 UNITED STAT E-SABSORBENT PRESS ROLL ASSEMBLY Earl E. Berry, Beloit, Wis., assignor toBeloit Iron Works, Beloit, Wis., a. corporation 01 Wisconsin ApplicationJune 28, 1937, Serial No. 150,683

3 Claims.

This invention relates to press rollassemblies wherein at least one ofthe rolls has a hard, porous surface adapted to absorb or otherwisereceive liquid pressed from a web of paper for conveyance of the liquidaway from the web.

More specifically this invention relates to press roll assemblies havinga hard but porous surfaced roll adapted to receive water therein forconveyance away from the nip between rolls of o the assembly togetherwith means spaced from the nip for cleaning and drying the poroussurface before the same reenters the nip.

In the patent to Wiley C. Smith No. 1,990,102, dated February 5, 1935,rolls having porous sur- [5 faces are described. The porous surfaces ofthese rolls are for receiving water therethrough. The porous surfacesare thus utilized for transmitting water to the interior of the roll,for-example, into a suction head.

Hard porous surfaces on press rolls, however, are better suited forconveying water away'from the hips of press roll assemblies than fortransmitting water therethrough at the nip of the assembly as in thecase of a suction press in which 25 the suction roll has a poroussurface, because a vacuum cannot be sustained in such a suction roll. Insuction rolls having hard, porous surfaces, even though the suction headof the roll is confined to a fixed area on the interior of the roll,

30 this area is unconfined at the exterior of the roll because of theporosity of the roll surface. As

a result, air will enter the roll surface from all directions and avacuum or suction area on the exterior of the roll cannot be maintained.

According to this invention, I utilize the porous surface of a pressroll to receive therein water squeezed out from a web and convey thewater entered into the surface of the roll away from the web. Duringthis conveyance, some of the water is thrown from the roll bycentrifugal force and remaining portions of the water are sucked orblown out of the roll at points spaced from the web. The roll surfacemay be washed prior to the sucking or blowing operation to clean thepores of the roll.

The porous roll surface allows water pressed from the web to entertherein in suflicient quantities to be carried through the nip insteadof ac cumulated back of the nip and thus prevents a 50 crushing of theweb as it passes through the nip. Further, a smoothing effect isobtained on the web since the web may be squeezed between two hardsurfaced rolls. Heretofore it has always been necessary to use anabsorbent felt between 55 the press rolls and the wet web if the webcontained above a certain amount of moisture dependent upon the type'ofstock from which it was formed. The felt marks the web appreciably. Thefelt marks are hard to remove from the web and added smoothing pressesare required for 5 removing the marks. The hard absorbent surfaced pressrolls of this invention do not mark the web but instead smooth the sameas well as extract water therefrom.

Many types of materials can be used to form the porous surfaces of theroll such as, for example, ceramic materials, .filter aids, refractorygrains such as silicon carbide and aluminum oxide and the like. Thesegranular materials can be bonded together with a vitreous material andbaked to form a hard cylinder of suflicient thickness so as to beself-sustaining or the materials and binder can be baked on a metal rollor cylinder to form a porous surface on said roll or cylinder. g It isthen an object of this invention to provide press roll assembliesincluding a porous surfaced roll.

Another object of this invention is to provide a press roll assemblyincluding a hard, porous surfaced roll for conveying water away from thenip of the assembly and for smoothing a web passed thru the nip.

A further object of this invention is to provide a press roll with ahard, porous surface and to removewater from this surface by mechanicalmeans positioned at points away fromthe point where the water enters thesurface.

A further object of this invention is to provide a press roll assemblyincluding a hard, porous surfaced roll and a suction device cooperatingwith the. outer surface of the roll to draw water from the poresthereof.

A further object of this invention is to provide a press roll assemblyincluding a hard, porous surfaced roll and a mechanical blower devicecooperating with the inner surface of the roll to blow water from thepores thereof.

Another object of this invention is to provide a process of dewateringwebs utilizing a hard, porous surface for conveying water away from theweb.

A further object of this invention is to provide a process of dewateringpaper sheets wherein water expressed from the sheets is absorbed in ahard, rotating surface and thrown out of said surface away from thesheets by centrifugal force.

Other and further objects of this invention will become apparent tothose skilled in the art from the following detailed description of theassembly.

annexed sheets of drawings which disclose preferred embodiments of theinvention.

On the drawings:

Figure 1 is a diagrammatical view of a press assembly according to thisinvention including a hard, porous surfaced bottom roll and acooperating top roll.

Figure 2 is a diagrammatic view of a horizontal press roll assemblyaccording to this invention utilizing a hard, porous surfaced roll inthe assembly.

Figure 3 is a diagrammatic'view of a press roll assembly according tothis invention including a rubber covered top roll.

Figure 4 is another diagrammatic view of a press roll assembly accordingto this invention wherein the hard, porous surfaced roll has aperforated supporting shell and a suction or blower head cooperatesthrough the foraminations of the shell to remove water from the pores ofthe surface material.

As shown on the drawings:

In Figure l the reference numeral l0 designates an absorbent carrierband such as a felt looped around guide rolls H and under a tensioningroll I2. The upper run of the felt l0 conveys a web W through the nip ofa press roll assembly comprising a porous surfaced roll !3 and a toproll l4 cooperating with the roll I3. The web W is preferably raised offof the felt l0 and directed over a lifting roll I5 before it enters thenip of the press roll assembly.

The press roll l3 of the assembly comprises a cylindrical metal sleevel6 having a porous shell l1 of granular material such as a ceramicmaterial, filter aid or the like, bonded thereon in integral relationtherewith. The shell I1 is full of minute pores and is adapted toreceive water pressed from the web W as it passes through the nip of theassembly therein. The water entering the shell I1 is conveyed in theshell through the nip of the assembly and away from the web W and feltH) as the roll l3 rotates. The rotation of the roll l3 effects acentrifugal discharge of some of the water in the pores of the shell l1,as shown at l8.

A shower pipe I9 is positioned adjacent the shell l1 for ejecting aspray of water 20 or other cleaning fluid against the shell to wash thesame. The spray 20 impinges upon the shell I1 at a point spaced from thenip of the assembly so that the water does not contact the felt or Web.

A suction box 2| communicates through seals 22 with the outer face ofthe shell l1 to draw out water from the pores of the shell. The suctionbox 2| may be evacuated and drained through an opening 23 in the endthereof.

The pores of the shell |1 are thus washed and have the water thereinremoved therefrom at points away from the nip area of the assembly sothat as the shell l1 rotates into the nip area the pores thereof are ina dried and cleaned condition.

The cooperating top roll I4 is adjustable as shown in dotted lines at Hrelative to the press roll 13 for varying the nip position of the Fromthe above description of Figure 1 it should be understood that a wet webW is received on an absorbent carrier band such as a felt and directedthrough a vertical two-press roll assembly including a press roll havinga porous water-absorbent surface capable of receiving therein waterexpressed from the web. This water enters the pores of the absorbentsurfaced roll and is conveyed in these pores through the nip of theassembly thereby preventing an accumulation of water back of the nipthat would tend to crush the web. As the absorbent surfaced roll rotatesaway from the nip, part of the water in the pores thereof is dischargedby centrifugal force and remaining portions of the water are sucked fromthe pores by a mechanical suction device cooperating with the outer faceof the roll.

In the press roll assembly shown in Figure 2, i the reference numeral 25designates a perforated suction roll; the reference numeral 26designates a plain metal press roll; and the reference numeral 21designates a porous surfaced press roll similar to the press roll 13.The rolls 25, 26 and 21 are horizontally arranged with their axes on thesame horizontal plane, or substantially the same plane. The end rolls 25and 21 are urged toward the center roll 26 to exert pressures in the twonips between the rolls.

An absorbent carrier band such as a felt 28 is trained around thesuction roll 25 and around a guide or tensiom'ng roll 29 positionedbelow the suction roll.

A wet web W is conveyed on the felt 28 around the roll 25, down throughthe first nip of the assembly, around the lower portion of the roll 26and up through the second nip of the assembly. From the second nip theweb W is directed around a guide roll 30 positioned above the assembly.

Water expressed from the web in the downward passage nip of the assemblyis sucked from the nip into a suction box 3i mounted in the suction roll25. The upward passage nip of the assembly is a free draining nip, butsome of the water expressed from the web in this nip enters the pores ofthe absorbent shell 32 of the press roll 21. This water in the pores ofthe shell 32 is conveyed away from the web W and partly discharged fromthe pores by centrifugal force as the pores begin their descendingpassage on the side of the roll opposite the upward passage nip Thepores are then Washed by a spray of water 33 ejected from a shower pipe34 at a point away from the nip. Remaining portions of water in thepores of the shell 32 are drawn from the pores by a suction box 35cooperating with the 50 outer face of the shell 32. Therefore the poresenter the nip in a cleaned and dried condition for receiving watertherein expressed from the web passing through the nip.

The web passes through the second nip of the l assembly shown in Figure2 unsupported by a felt and directly contacts the hard surfaces of therolls 26 and 21 which smooth and iron out the web. Since the porousshell 32 removes water from the nip the web will not be crushed therebyeliminating the heretofore necessary absorbent felt and the addedsmoothing presses for removing felt marks from the web.

In Figure 3, the press roll assembly comprises a bottom roll 36 and acooperating top roll 31 65 receiving a web W through the niptherebetween. The roll'36 is made of a vitreous bonded porous materialof sufiicient thickness to be self-sustain ing. The roll 31 isrubber-covered.

A shower pipe 38 ejects a spray of water or other cleansing fluid 39against the outer face of the-roll 36, at a point spaced from the nip ofthe assembly.

A suction box 40 is positioned adjacent the roll 36 at or near thebottom of the roll for drawing water or liquid out of the pores of theroll.

A burner head 4| may be positioned after the suction box 40 for ejectinga flame 42 or a plurality of flames against the outer surface of theroll to burn off fibers or other impurities remaining in the pores ofthe roll after the suction treatment. The flame 42 will further dry theroll.

A web of paper W enters the nip of the assembly in the directionindicated by the arrow and the rolls 36 and 31 express water from theweb. This water is absorbed into the pores of the roll 36 and conveyedthrough the nip of the assembly away from the web where it is partiallydischarged from the pores by centrifugal force as at 43. The pores arethen washed by a spray 39 and sucked dry by the suction box 40. Then ifdesired the porous material can be further treated by heat before thetreated pores reenter the nip area. The use of the porous surfaced rollprevents accumulation of water back of the nip since this Water isabsorbed into the pores of the roll.

In Figure 4 a two-press roll assembly comprising a top roll 44 and abottom roll 45 receives a wet web W in the nip therebetween.

The roll 45 comprises a foraminous sleeve or supporting mandrel 46having a shell 41 of porous material bonded thereon.

A box or head 48 is positioned in the sleeve 46 and carries seals 49rubbing against the inner surface of the sleeve. The interior of the boxcommunicates through a slot 50 with an area of the sleeve between theseals 49.

Compressed air from a blower (not shown) may enter the box 48 through anopening 5| in the end thereof and is ejected throughthe slot 50 againstthe inner surface of the sleeve 46 from which it travels through theforaminations thereof to blow water out of the pores of the shellmaterial 41.

A shower pipe such as is shown in Figures 1 to 3 can also be used intheassembly shown in Figure 4.

In the assembly shown in Figure 4, the web W enters the nip of the rolls44 and 45 and water is expressed from the web by pressure exerted by therolls. This water is absorbed into thepores of the surface material 41of the roll 45 and conveyed through the nip in these pores. Part of thewater is then discharged by centrifugal force as the pores rotate awayfrom the web and the remaining portions of the water in the pores areeither blown out of the pores by an air blast.

or are sucked out of the pores by suction.

I am aware that many changes may be made and numerous details ofconstruction may be varied through a wide range without departing fromthe principles of this invention, and I, therefore, do not purposelimiting the patent granted hereon otherwise than necessitated by theprior art.

I claim as my invention:

1. A press roll assembly comprising-three rolls in pressure relationhaving their axes on substantially the same horizontal plane to define adownward passage nip and an upward passage 'nip for a web of paper, asuction device for removing water from the downward passage nip, acylindrical water absorbent stone-like shell full of minute pores on aroll defining the upward passage nip adapted to receive water in thepores thereof for conveyance away from a web passing through theassembly, and a suction box cooperating with the outer surface of thecylindrical shell at a point spaced from the upward passage nip fordrawing water out of the pores of the shell.

2. The method of dewatering wet webs which comprises passing a wet webthrough the nip between a roller having a hard, porous surface andanother roller to express water from the web, immediately absorbing theexpressed water into the pores of said porous surface, conveying thewater in said pores through the nip and away from the web, removingwater from the pores at a point remote from the nip and web, directing aflame against the porous surface after said removal of water to heat thesurface and continually supplying dewatered and heat-treated pores tothe nip.

3. A horizontal press roll assembly including three rolls in pressurerelation having their axes in substantial horizontal alignment to definean upward passage nip and a downward passage nip, a relatively thickhard stone-like cover on one of said rolls having minute water-absorbentpores extending in all directions and adapted to receive therein watersqueezed from a web passing through the nip partially defined therebyfor conveyance away from the web, and means remote from the nip and webcooperating with the cover to draw the water out of the pores before thesame re-enters the nip.

- EARL E. BERRY.

